News from the Alberta Recreational Lakes Forum 2017

Alberta Environment and Parks organized this year’s forum at Lake Isle west of Edmonton.

Several forum documents and presentations are filed in this online SLWSS folder.

The SLWSS did not attend this year’s forum as the need for input from community stewardship groups has declined. We did provide this report on our 2016 activities and projects:

SLWSS REPORT FOR THE ALBERTA RECREATIONAL LAKES (ARL) FORUM 2017

State of the Watershed 2016

Our comprehensive report “The Sylvan Lake Watershed-Second Edition” documented changes in the key indicators that affect the state of the watershed. Data on Environmental, Social and Economic Cumulative Effects variables were compiled for time periods of one or more decades and presented a picture of a relatively stable environment.

Water Quality Monitoring 2016

Preliminary analytical data indicate that in a year with little spring runoff the nitrogen and phosphorus nutrient concentrations have been lower than the long-term average. The lake water clarity remained very high with Secchi disk depth measurements typically greater than 5 metres. Photo albums of the lake sampling expeditions were posted on our SLWSS News blog site.

Nature Alberta’s Living by Water Program

The Society has promoted the Nature Alberta Living by Water program for several years and enabled more than 80 property owners to benefit from Home Assessments. Response to L by W has declined and we awarded a SLWSS yard sign to just a single property owner in 2016.

Government Affairs in 2016

The Society presented a statement on the potential impact of the West Area structure plan at a public hearing of the Town of Sylvan Lake with regard to transport of silt from construction sites through Marina Bay into Sylvan Lake in Golf Course Creek runoff. We recorded several cases of increased turbidity in stormwater runoff.

Groundwater Research

We assisted a University of Calgary geophysics survey team led by Profs. Lauer and Bentley to collect groundwater aquifer data at the west end of Sylvan Lake in October.

Quiet Enjoyment Initiative

The QEI subcommittee chaired by Kent Lyle continued its efforts to have local municipal bylaws adopted to control the sources of noise on the lake. An education and boat launch site signage project was developed at the request of the SLMC. Subsequent support by the municipal members of the SLMC was mixed and disappointing to the hard-working sub-committee. The QEI message resonated with and received considerable major and local media interest in its efforts to promote respect for others. An expanded QEI subcommittee report is posted here.

Community Outreach

Our ceramic tile for the new lighthouse is mounted on the structure with inscription: “Sylvan Lake Watershed Stewardship Society: Protecting the lake’s natural assets and values through vigilance and science”.

 

 

 

The Safe Boating Guide Applies to You

The open water season is near so preparation for boating will start soon. A helpful place to begin is with a checkup on the boating regulations that apply to pleasure craft as explained in the Safe Boating Guide.

safe-boating-banner

Anyone with a Pleasure Craft Operator’s Card should already know the rules. Help Sylvan Lake by applying them.

As Sylvan Lake is one of Alberta’s recreational lakes, boaters are welcome to have fun.

In return, Sylvan Lake’s watershed stewards expect that water quality and the aquatic and terrestrial environments will be respected and protected. That’s what responsible boaters do.

The key lake-protection points are worth repeating.

DON’T DON’T DON’T DON’T:

Be a responsible boater because others are watching you.

Keep your passengers safe.

 

 

 

So what’s happening to Sylvan Lake water quality these days?

Lake and tributary monitoring continued in 2014 with an expanded scope and detective work. Diagnostic water quality data from the open water season are still being analyzed by both the ALMS LakeWatch team and by our own tributary samplers and all should be available before the end of March 2015. While we wait, four decades of data in the Alberta Environment water quality database help to indicate the state of the lake and impact of the surrounding watershed and its progressive urbanization.

Is the lake getting better or worse over time? Here’s what we know:

1. Does the lake appear to be more or less transparent than it used to be?

Simple Secchi disk observations tell us this:

Secchi Disk Transparency

The detectability of a submerged Secchi disk has varied erratically from as shallow as 2 meters (m) to 8 m even in a single year. That is a measure of the quantity of suspended light-scattering particles in the water column. More algae, or fine minerals from shoreline erosion, cause a shallow reading while fewer particles allow the disk to still be seen at greater depths.

2. Is the lake more or less green than it used to be?

Here are results from lab analysis of the green Chlorophyll-a pigment found in algae and other plant material:

Chlorophyll-a DataChlorophyll-a Molecule

The Chlorophyll-a molecule found in green plants helps to convert CO2 to O2.

Over the 30-year period shown, the chlorophyll-a data seem to have declined although in any year values can change significantly through the open-water season. Other factors affect algae growth including available plant nutrients in the water, sunlight, and water temperature.

3. Are the Secchi disk measurements affected by algae in Sylvan Lake?

Here is the graph that relates the two variables:

Secchi vs Chlorophyll-a Data

In general, higher water clarity (larger Secchi disk depth) is found  when Chlorophyll-a is low. However, because algae tend to float near the lake surface where light can penetrate we should not expect that the two measurements will be highly correlated.

4. Do nutrient concentrations that are transported into Sylvan Lake in tributaries cause algal blooms?

The simple answer is that nitrogen (N), phosphorus (P), potassium (K) and other elements in Sylvan Lake’s water are essential for growth and are absorbed by plants. Many studies of lakes have shown that phosphorus can be a limiting growth factor. We use the standard Total Phosphorus lab analyses as one convenient indicator of the potential for algal blooms. The data collected since 1982 show that the TP concentration has varied around a mean value of 21 micrograms per litre with a standard deviation of about 5 micrograms/L. That means 95% of the data fall between about 11 and 31 micrograms/L during three decades of water quality testing. The important TP concentration (and the associated Dissolved Phosphorus concentration, the active form for plant uptake) has not changed much, likely because of a lucky balance between annual lake loading in runoff and annual loss to the lake-bottom sediments as algae, cyanobacteria and plants die.

TP in Sylvan Lake5. Are the green Chlorophyll-a and Total Phosphorus nutrient concentrations related?

Let’s test it with a scatter plot of one variable against the other. Here is the graph of Chlorophyll-a plotted against TP:

Chlorophyll-a vs TP

The correlation between the two variables is poor. For example over the years of observation, at TP of 20 micrograms/L , chlorophyll-a has been found to vary from almost zero to 10 micrograms/L. And, at a reference value of 5 ug/L of chlorophyll-a, TP has varied between 15 and 30  ug/L. The statistical distributions of each variable are broad. Without measurements of all the other variables that affect chlorophyll-a we can only assume that algae growth and phosphorus nutrient concentrations should be related.

Qualitatively, the data do indicate that TP has rarely exceeded the Alberta Surface Water Quality Guideline (ASWQG) of 35 ug/L that is recommended for Sylvan Lake. The empirical evidence continues to support a lack of chronic algal/cyanobacterial blooms in Sylvan Lake. A systematic tributary monitoring program that measures nutrient transport into the lake is essential to detect any threat of increased lake loading by plant fertilizers.

6. Are there any other indicators of longer term water quality changes?

This graph shows that other common ions in Sylvan Lake have been increasing over time:

Common Ions in Sylvan LakeCl in Sylvan Lake 1983-2005

Inflowing surface and groundwater contains dissolved minerals and agricultural and urban contaminants. Continuous evaporation of lake water slowly concentrates those ions which are not lost to lake sediments by adsorption, ion exchange, or precipitation. The first graph shows that sodium, potassium, and chloride have increased since 1983. The second figure expands the concentration scale to show that chloride ion (the bottom line in the left hand graph) has increased almost three times since 1982. The most likely sources of chloride in the watershed are road salt and domestic water softener applications. Increasing chloride, while dilute, is a direct indicator of human impact on the lake.

7. How can we understand all this information? What can we do to protect Sylvan Lake?

It’s easy. You just have to know the Two Laws of the Watershed:

1. Water flows downhill.

So you can easily tell where water is coming from, and going to.

2. Stuff from the land ends up in the lake.

Sylvan Lake is like a slightly leaky bathtub. More natural and urban wastes enter the tub than leave through the drain.

Protection of Sylvan Lake requires that all contaminated surface runoff and stormwater be collected and cleaned up before it is discharged into the lake, or diverted out of the watershed in municipal stormwater sewers. New urban development that covers land with buildings and roads prevents water infiltration that presently replenishes groundwater supplies and increases the volume and rate of runoff. Diversion of snow melt and precipitation runoff that flows downhill will eventually affect the watershed’s water balance.

Understand the Two Laws, then common sense will let you create your own lake protection solutions.

 

 

 

Analysis of Sylvan Lake Level, and Control Options

Terry Chamulak, an Alberta Environment and Sustainable Resource Development regional hydrologist, has completed a detailed study of how Sylvan Lake levels have changed between 1940 and 2012. He used a water balance model to reproduce the annual and longer term cyclical changes in the lake level and examined the performance of the lake outflow through Outlet Creek.

In a second report, Chamulak evaluated the possible effects of several outflow modification concepts that might be used to control the lake level. As Sylvan Lake’s level is determined by seasonal climate and weather conditions (precipitation and evaporation and the annual difference between those two large volumes of water), increasing the lake’s outflow for the convenience of beach goers would likely have negative impacts on others in the watershed.

Natural cycling of the lake level would still continue if the lake level was arbitrarily lowered.

Both reports are in final stages of editing and the linked versions should be treated as draft documents. Note that the first report is a 2 MB and the second one is a 6 MB download.

Precipitation Record for the Sylvan Lake Region over 70 Years

Water that ends up in Sylvan Lake starts out as rain and snow precipitation that falls within the watershed boundary. There are no other sources of water input. Precipitation that falls directly onto the lake surface plus runoff and urban stormwater from the land, and groundwater that enters the lake underground all affect the lake level. Check the Water Quantity category on this website for other postings on this topic.

Historically the lake level in mid-Summer has been about 936.75 metres above sea level according to Alberta Environment records. The current lake level is 937.2 metres, significantly above the long term average high water mark of about 937.0 metres.

Has the extra water come from higher-than-usual precipitation? Here are the facts:

Seventy years of Total Precipitation data collected at the Red Deer Airport between 1940 and 2011 are plotted in this graph. That weather station is  a reliable Environment Canada WeatherOffice site and its data should represent Sylvan Lake’s weather in the absence of a station located within the watershed. The average annual Total Precipitation in the region has been 0.466 metres. The amount has varied between a high of 0.63 meter and a low of 0.29 metre during the 70 year period.

Total Precipitation can vary dramatically from year to year. This graph shows the year-to-year change since 1940. Differences since 2000 are within the historic range.

Statistically speaking, during the last 70 years annual total precipitation values have been within +/- 10 percent of the average about 80 percent of the time. In 15 percent of the years the values have been up to 37 percent greater than the average. In 11 percent of the years the values have been up to 40 percent below the average. See the analysis of all the data in this graph.

As the Total Precipitation record for the region has not changed much over 70 years but the Sylvan Lake level is above the long term average high water mark shown here, then other factors like the evaporation rate must be controlling the quantity of water in Sylvan Lake.

Erosion of the Sylvan Lake Provincial Park Beach in 2012

Another June storm with strong northwest winds drove more waves into the southeast shore that is the main attraction for visitors. The following slide show records the state of the shore along the recreational waterfront. The sections that are still protected by engineered structures remain intact. Unprotected shoreline and the walking path are eroded and in many locations they are unsafe. Some trees and bushes along the lake edge are at risk from undercutting of the bank and they will eventually fall into the lake.

 

Click on any photo to enlarge it.